package com.hmdp.utils;

import cn.hutool.core.io.resource.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.data.redis.connection.DefaultedRedisConnection;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;

import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock {

    private String name;
    private StringRedisTemplate stringRedisTemplate;

    private static final String KEY_PREFIX = "lock:";
    private static final String ID_PREFIX = UUID.randomUUID().toString() + "-";
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;

    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation((Resource) new ClassPathResource("unlock.lua"));
        UNLOCK_SCRIPT.setResultType(Long.class);
    }

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public boolean tryLock(long timeoutSec) {
        //获取线程标识
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        //获取锁
        Boolean success = stringRedisTemplate.opsForValue()
                .setIfAbsent(KEY_PREFIX+name,threadId,timeoutSec , TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);//避免自动拆箱空指针异常
    }


    @Override
    public void unlock(){
        stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX+name),
                ID_PREFIX+Thread.currentThread().getId()
        );
    }
//    @Override
//    public void unlock() {
//        //获取线程标识
//        String threadId = ID_PREFIX+Thread.currentThread().getId();
//        //获取锁中的标识
//        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX+name);
//        //判断标识是否一致
//        if (threadId.equals(id)) {
//            //释放锁
//            stringRedisTemplate.delete(KEY_PREFIX+name);
//        }
//        stringRedisTemplate.delete(KEY_PREFIX+name);
//    }
}
